The A3977xED and A3977xLP are complete microstepping motor drivers with built-in translators. They are designed to operate bipolar stepper motors in full-, half-, quarter-, and eighth-step modes, with output drive capability of 35 V and ±2.5 A. The A3977 includes a fixed off-time current regulator that has the ability to operate in slow-, fast-, or mixed-decay modes. This current- decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation. The translator is the key to the easy implementation of the A3977. By simply inputting one pulse on the STEP input the motor will take one step (full, half, quarter, or eighth depending on two logic inputs). There are no phase detection, so the motor can be used with or without a Hall sensor driver. The A3977 can be connected to an external microcontroller via a separate I2C port to implement more advanced features.